Figure 2.

ROC analysis and comparison of FR+ CTC levels between subgroups. (A) ROC curves for diagnosis of lung cancer by FR+ CTCs; (B) the FR+ CTC levels in malignant vs. benign space-occupying lesions; (C) the FR+ CTC levels in different pathological subtypes of lung cancer; (D) the FR+ CTC levels in different benign respiratory diseases with space-occupying lesions. ROC, receiver operating characteristic; FR+ CTC, folate receptor-positive circulating tumor cells; ADC, adenocarcinoma; SCC, squamous cell carcinoma; SCLC, small cell lung cancer; NSCLC, non-small cell lung cancer.